SUMMARY
This method imparts bioadhesive properties onto polymeric semiconductors, which enables effective transductions of bio-signals from biological tissues to electronic devices.
The Unmet Need: Conformable and stable integration of semiconductor-based biosensing surfaces with wet tissues
Integrating biocompatible electronic devices with living biological tissues is emerging as a highly promising avenue for achieving the real-time measurement of biological signals with high spatiotemporal resolutions for health monitoring.
An overarching goal for the development of bioelectronic devices is to achieve conformable and stable interfacing between the sensing surface and the tissue, which can only be realized by combining two aspects:
- Soft and stretchable properties on devices for adapting to curvilinear tissue surfaces
- Stable bonding between the electrical sensing surface and the tissue
While stretchable bioelectronic materials and devices have been explored, they lack the adhesive properties needed to adhere to tissues.
Additionally, neither the conventional periphery fixation through suturing or stapling nor applying a separate adhesive gives conformable contact and low impedance. The more desired interfacing is to have the semiconducting channel directly adhere to the tissue surface.
The Proposed Solution: Bioadhesive polymer Semiconductor
The inventors have developed a bioadhesive polymer semiconductor through a double-network structure formed by combining a newly designed bioadhesive brush polymer and a redox-active semiconducting polymer.
The incorporation of tissue-adhesive groups with the brush design enables the resulting semiconducting film to form rapid and strong adhesion with wet tissue surfaces. Meanwhile, the percolated semiconductor phase in the film keeps high charge-carrier mobility of ~0.5 cm2 V-1 s-1. This bioadhesive polymer semiconductor also exhibits:
- Abrasion resistance
- High stretchability
- Tissue-level modulus
- Good biocompatibility
The researchers have fabricated a fully-bioadhesive transistor sensor which enabled them to produce high-quality and stable epicardial electrocardiogram recordings on an isolated rat heart.
FIGURE
Bioadhesive polymer semiconductors for electrochemical-transistor-based tissue interfacing.
(A) Use of electrochemical transistors at tissue interfaces for biosensing with built-in amplification, for which bio-signals couple into the polymer semiconductor channels through direct tissue contact. (B to C) Conventional device attachment methods on tissue surfaces, such as peripheral suturing and applying a non-electrical adhesive layer, and their corresponding limitations. (D) Direct adhesive attachment achieved by a bioadhesive polymer semiconducting (BASC) channel and a wet tissue surface. The double-network design of the BASC contains a semiconducting polymer and an adhesive polymer achieving covalent bonding with tissue surfaces. (E) Chemical structures of the adhesive monomers with even longer linear side chains terminated with NHS ester and COOH groups, and the schematic of formed brush-architectured bioadhesive polymer (BAP). (F) Chemical structure and a schematic of the utilized polymer semiconductor p(g2T-T) with long linear side chains. (G) Photograph showing a fully-bioadhesive OECT with BASC channel adhered to a rat heart for ECG recording, which can stand for mechanical agitations
ADVANTAGES
Advantages
- Strong and fast adhesion with wet-tissue surfaces
- High electrical performance
- Abrasion resistance
- High amplification
- Low operation voltage
- Intrinsic compatibility with ion-based biological events
- Tissue-like stretchability
Applications
- Biocompatible electronic devices
- Health monitoring
- Adhesive sensors
- Underwater sensing
PUBLICATIONS
March 1, 2024
Proof of concept
Patent Pending
Licensing,Co-development
Sihong Wang